Recent state-of-the-art one-stage instance segmentation model SOLO divides the input image into a grid and directly predicts per grid cell object masks with fully-convolutional networks, yielding comparably good performance as traditional two-stage Mask R-CNN yet enjoying much simpler architecture and higher efficiency. We observe SOLO generates similar masks for an object at nearby grid cells, and these neighboring predictions can complement each other as some may better segment certain object part, most of which are however directly discarded by non-maximum-suppression. Motivated by the observed gap, we develop a novel learning-based aggregation method that improves upon SOLO by leveraging the rich neighboring information while maintaining the architectural efficiency. The resulting model is named SODAR. Unlike the original per grid cell object masks, SODAR is implicitly supervised to learn mask representations that encode geometric structure of nearby objects and complement adjacent representations with context. The aggregation method further includes two novel designs: 1) a mask interpolation mechanism that enables the model to generate much fewer mask representations by sharing neighboring representations among nearby grid cells, and thus saves computation and memory; 2) a deformable neighbour sampling mechanism that allows the model to adaptively adjust neighbor sampling locations thus gathering mask representations with more relevant context and achieving higher performance. SODAR significantly improves the instance segmentation performance, e.g., it outperforms a SOLO model with ResNet-101 backbone by 2.2 AP on COCO \texttt{test} set, with only about 3\% additional computation. We further show consistent performance gain with the SOLOv2 model.

We present a new, embarrassingly simple approach to instance segmentation. Compared to many other dense prediction tasks, e.g., semantic segmentation, it is the arbitrary number of instances that have made instance segmentation much more challenging. In order to predict a mask for each instance, mainstream approaches either follow the "detect-then-segment" strategy (e.g., Mask R-CNN), or predict embedding vectors first then use clustering techniques to group pixels into individual instances. We view the task of instance segmentation from a completely new perspective by introducing the notion of "instance categories", which assigns categories to each pixel within an instance according to the instance's location and size, thus nicely converting instance segmentation into a single-shot classification-solvable problem. We demonstrate a much simpler and flexible instance segmentation framework with strong performance, achieving on par accuracy with Mask R-CNN and outperforming recent single-shot instance segmenters in accuracy. We hope that this simple and strong framework can serve as a baseline for many instance-level recognition tasks besides instance segmentation. Code is available at https://git.io/AdelaiDet

最近，DETR通过变压器启动了视觉任务的解决方案，它直接将图像特征映射转换为对象检测结果。虽然有效，但翻译完整的特征映射可能是由于背景的某些区域的冗余计算而成本。在这项工作中，我们封装了将空间冗余降低到新型民意调查和池（PNP）采样模块中的想法，其中我们构建了一个端到端的PNP-DETR架构，可在空间上自适应地分配其计算以更有效。具体地，PNP模块将图像特征映射到精细的前景对象特征向量和少量粗糙背景上下文特征向量。变压器模型在细粗糙度空间内的信息交互，并将要素转化为检测结果。此外，通过改变采样的特征长度，PNP - 增强模型可以通过单个模型立即在性能和计算之间实现各种期望的权衡，而不需要将多个模型作为现有方法训练。因此，在不同的情况下，它提供了更大的部署灵活性，不同的情况下具有不同的计算约束。我们进一步验证了PNP模块对Panoptic分割和最近的基于变压器的图像识别模型VIT的普遍性，并显示了一致的效率增益。我们相信我们的方法对变压器进行有效的视觉视觉分析，其中通常观察到空间冗余。代码将在\ url {https://github.com/twangnh/pnp-detr}上使用。

In contrast to fully supervised methods using pixel-wise mask labels, box-supervised instance segmentation takes advantage of simple box annotations, which has recently attracted increasing research attention. This paper presents a novel single-shot instance segmentation approach, namely Box2Mask, which integrates the classical level-set evolution model into deep neural network learning to achieve accurate mask prediction with only bounding box supervision. Specifically, both the input image and its deep features are employed to evolve the level-set curves implicitly, and a local consistency module based on a pixel affinity kernel is used to mine the local context and spatial relations. Two types of single-stage frameworks, i.e., CNN-based and transformer-based frameworks, are developed to empower the level-set evolution for box-supervised instance segmentation, and each framework consists of three essential components: instance-aware decoder, box-level matching assignment and level-set evolution. By minimizing the level-set energy function, the mask map of each instance can be iteratively optimized within its bounding box annotation. The experimental results on five challenging testbeds, covering general scenes, remote sensing, medical and scene text images, demonstrate the outstanding performance of our proposed Box2Mask approach for box-supervised instance segmentation. In particular, with the Swin-Transformer large backbone, our Box2Mask obtains 42.4% mask AP on COCO, which is on par with the recently developed fully mask-supervised methods. The code is available at: https://github.com/LiWentomng/boxlevelset.

现有的实例分割方法已经达到了令人印象深刻的表现，但仍遭受了共同的困境：一个实例推断出冗余表示（例如，多个框，网格和锚点），这导致了多个重复的预测。因此，主流方法通常依赖于手工设计的非最大抑制（NMS）后处理步骤来选择最佳预测结果，这会阻碍端到端训练。为了解决此问题，我们建议一个称为Uniinst的无盒和无端机实例分割框架，该框架仅对每个实例产生一个唯一的表示。具体而言，我们设计了一种实例意识到的一对一分配方案，即仅产生一个表示（Oyor），该方案根据预测和地面真相之间的匹配质量，动态地为每个实例动态分配一个独特的表示。然后，一种新颖的预测重新排列策略被优雅地集成到框架中，以解决分类评分和掩盖质量之间的错位，从而使学习的表示形式更具歧视性。借助这些技术，我们的Uniinst，第一个基于FCN的盒子和无NMS实例分段框架，实现竞争性能，例如，使用Resnet-50-FPN和40.2 mask AP使用Resnet-101-FPN，使用Resnet-50-FPN和40.2 mask AP，使用Resnet-101-FPN，对抗AP可可测试-DEV的主流方法。此外，提出的实例感知方法对于遮挡场景是可靠的，在重锁定的ochuman基准上，通过杰出的掩码AP优于公共基线。我们的代码将在出版后提供。

分割高度重叠的图像对象是具有挑战性的，因为图像上的真实对象轮廓和遮挡边界之间通常没有区别。与先前的实例分割方法不同，我们将图像形成模拟为两个重叠层的组成，并提出了双层卷积网络（BCNET），其中顶层检测到遮挡对象（遮挡器），而底层则渗透到部分闭塞实例（胶囊）。遮挡关系与双层结构的显式建模自然地将遮挡和遮挡实例的边界解散，并在掩模回归过程中考虑了它们之间的相互作用。我们使用两种流行的卷积网络设计（即完全卷积网络（FCN）和图形卷积网络（GCN））研究了双层结构的功效。此外，我们通过将图像中的实例表示为单独的可学习封闭器和封闭者查询，从而使用视觉变压器（VIT）制定双层解耦。使用一个/两个阶段和基于查询的对象探测器具有各种骨架和网络层选择验证双层解耦合的概括能力，如图像实例分段基准（可可，亲戚，可可）和视频所示实例分割基准（YTVIS，OVIS，BDD100K MOTS），特别是对于重闭塞病例。代码和数据可在https://github.com/lkeab/bcnet上找到。

两阶段和基于查询的实例分段方法取得了显着的结果。然而，他们的分段面具仍然非常粗糙。在本文中，我们呈现了用于高质量高效的实例分割的掩模转发器。我们的掩模转发器代替常规密集的张量，而不是在常规密集的张量上进行分解，并表示作为Quadtree的图像区域。我们基于变换器的方法仅处理检测到的错误易于树节点，并并行自我纠正其错误。虽然这些稀疏的像素仅构成总数的小比例，但它们对最终掩模质量至关重要。这允许掩模转换器以低计算成本预测高精度的实例掩模。广泛的实验表明，掩模转发器在三个流行的基准上优于当前实例分段方法，显着改善了COCO和BDD100K上的大型+3.0掩模AP的+3.0掩模AP的大余量和CityScapes上的+6.6边界AP。我们的代码和培训的型号将在http://vis.xyz/pub/transfiner提供。

We present a conceptually simple, flexible, and general framework for object instance segmentation. Our approach efficiently detects objects in an image while simultaneously generating a high-quality segmentation mask for each instance. The method, called Mask R-CNN, extends Faster R-CNN by adding a branch for predicting an object mask in parallel with the existing branch for bounding box recognition. Mask R-CNN is simple to train and adds only a small overhead to Faster R-CNN, running at 5 fps. Moreover, Mask R-CNN is easy to generalize to other tasks, e.g., allowing us to estimate human poses in the same framework. We show top results in all three tracks of the COCO suite of challenges, including instance segmentation, bounding-box object detection, and person keypoint detection. Without tricks, Mask R-CNN outperforms all existing, single-model entries on every task, including the COCO 2016 challenge winners. We hope our simple and effective approach will serve as a solid baseline and help ease future research in instance-level recognition. Code will be made available.

本文提出了一种用于对象和场景的高质量图像分割的新方法。灵感来自于形态学图像处理技术中的扩张和侵蚀操作，像素级图像分割问题被视为挤压对象边界。从这个角度来看，提出了一种新颖且有效的\ textBF {边界挤压}模块。该模块用于从内侧和外侧方向挤压对象边界，这有助于精确掩模表示。提出了双向基于流的翘曲过程来产生这种挤压特征表示，并且设计了两个特定的损耗信号以监控挤压过程。边界挤压模块可以通过构建一些现有方法构建作为即插即用模块，可以轻松应用于实例和语义分段任务。此外，所提出的模块是重量的，因此具有实际使用的潜力。实验结果表明，我们简单但有效的设计可以在几个不同的数据集中产生高质量的结果。此外，边界上的其他几个指标用于证明我们对以前的工作中的方法的有效性。我们的方法对实例和语义分割的具有利于Coco和CityCapes数据集来产生重大改进，并且在相同的设置下以前的最先进的速度优于先前的最先进的速度。代码和模型将在\ url {https:/github.com/lxtgh/bsseg}发布。

本文介绍了端到端的实例分段框架，称为SOIT，该段具有实例感知变压器的段对象。灵感来自Detr〜\ Cite {carion2020end}，我们的方法视图实例分段为直接设置预测问题，有效地消除了对ROI裁剪，一对多标签分配等许多手工制作组件的需求，以及非最大抑制（ nms）。在SOIT中，通过在全局图像上下文下直接地将多个查询直接理解语义类别，边界框位置和像素 - WISE掩码的一组对象嵌入。类和边界盒可以通过固定长度的向量轻松嵌入。尤其是由一组参数嵌入像素方面的掩模以构建轻量级实例感知变压器。之后，实例感知变压器产生全分辨率掩码，而不涉及基于ROI的任何操作。总的来说，SOIT介绍了一个简单的单级实例分段框架，它是无乐和NMS的。 MS Coco DataSet上的实验结果表明，优于最先进的实例分割显着的优势。此外，在统一查询嵌入中的多个任务的联合学习还可以大大提高检测性能。代码可用于\ url {https://github.com/yuxiaodonghri/soit}。

Cascade is a classic yet powerful architecture that has boosted performance on various tasks. However, how to introduce cascade to instance segmentation remains an open question. A simple combination of Cascade R-CNN and Mask R-CNN only brings limited gain. In exploring a more effective approach, we find that the key to a successful instance segmentation cascade is to fully leverage the reciprocal relationship between detection and segmentation. In this work, we propose a new framework, Hybrid Task Cascade (HTC), which differs in two important aspects: (1) instead of performing cascaded refinement on these two tasks separately, it interweaves them for a joint multi-stage processing; (2) it adopts a fully convolutional branch to provide spatial context, which can help distinguishing hard foreground from cluttered background. Overall, this framework can learn more discriminative features progressively while integrating complementary features together in each stage. Without bells and whistles, a single HTC obtains 38.4% and 1.5% improvement over a strong Cascade Mask R-CNN baseline on MSCOCO dataset. Moreover, our overall system achieves 48.6 mask AP on the test-challenge split, ranking 1st in the COCO 2018 Challenge Object Detection Task. Code is available at: https://github.com/ open-mmlab/mmdetection.

In this paper, we introduce an anchor-box free and single shot instance segmentation method, which is conceptually simple, fully convolutional and can be used by easily embedding it into most off-the-shelf detection methods. Our method, termed PolarMask, formulates the instance segmentation problem as predicting contour of instance through instance center classification and dense distance regression in a polar coordinate. Moreover, we propose two effective approaches to deal with sampling high-quality center examples and optimization for dense distance regression, respectively, which can significantly improve the performance and simplify the training process. Without any bells and whistles, PolarMask achieves 32.9% in mask mAP with single-model and single-scale training/testing on the challenging COCO dataset.For the first time, we show that the complexity of instance segmentation, in terms of both design and computation complexity, can be the same as bounding box object detection and this much simpler and flexible instance segmentation framework can achieve competitive accuracy. We hope that the proposed PolarMask framework can serve as a fundamental and strong baseline for single shot instance segmentation task. Code is available at: github.com/xieenze/PolarMask.

We propose a simple yet effective instance segmentation framework, termed CondInst (conditional convolutions for instance segmentation). Top-performing instance segmentation methods such as Mask R-CNN rely on ROI operations (typically ROIPool or ROIAlign) to obtain the final instance masks. In contrast, we propose to solve instance segmentation from a new perspective. Instead of using instancewise ROIs as inputs to a network of fixed weights, we employ dynamic instance-aware networks, conditioned on instances. CondInst enjoys two advantages: 1) Instance segmentation is solved by a fully convolutional network, eliminating the need for ROI cropping and feature alignment.2) Due to the much improved capacity of dynamically-generated conditional convolutions, the mask head can be very compact (e.g., 3 conv. layers, each having only 8 channels), leading to significantly faster inference. We demonstrate a simpler instance segmentation method that can achieve improved performance in both accuracy and inference speed. On the COCO dataset, we outperform a few recent methods including welltuned Mask R-CNN baselines, without longer training schedules needed.

Open vocabulary object detection has been greatly advanced by the recent development of vision-language pretrained model, which helps recognize novel objects with only semantic categories. The prior works mainly focus on knowledge transferring to the object proposal classification and employ class-agnostic box and mask prediction. In this work, we propose CondHead, a principled dynamic network design to better generalize the box regression and mask segmentation for open vocabulary setting. The core idea is to conditionally parameterize the network heads on semantic embedding and thus the model is guided with class-specific knowledge to better detect novel categories. Specifically, CondHead is composed of two streams of network heads, the dynamically aggregated head and the dynamically generated head. The former is instantiated with a set of static heads that are conditionally aggregated, these heads are optimized as experts and are expected to learn sophisticated prediction. The latter is instantiated with dynamically generated parameters and encodes general class-specific information. With such a conditional design, the detection model is bridged by the semantic embedding to offer strongly generalizable class-wise box and mask prediction. Our method brings significant improvement to the state-of-the-art open vocabulary object detection methods with very minor overhead, e.g., it surpasses a RegionClip model by 3.0 detection AP on novel categories, with only 1.1% more computation.

在本文中，我们提出了简单的关注机制，我们称之为箱子。它可以实现网格特征之间的空间交互，从感兴趣的框中采样，并提高变压器的学习能力，以获得几个视觉任务。具体而言，我们呈现拳击手，短暂的框变压器，通过从输入特征映射上的参考窗口预测其转换来参加一组框。通过考虑其网格结构，拳击手通过考虑其网格结构来计算这些框的注意力。值得注意的是，Boxer-2D自然有关于其注意模块内容信息的框信息的原因，使其适用于端到端实例检测和分段任务。通过在盒注意模块中旋转的旋转的不变性，Boxer-3D能够从用于3D端到端对象检测的鸟瞰图平面产生识别信息。我们的实验表明，拟议的拳击手-2D在Coco检测中实现了更好的结果，并且在Coco实例分割上具有良好的和高度优化的掩模R-CNN可比性。 Boxer-3D已经为Waymo开放的车辆类别提供了令人信服的性能，而无需任何特定的类优化。代码将被释放。

大多数最先进的实例级人类解析模型都采用了两阶段的基于锚的探测器，因此无法避免启发式锚盒设计和像素级别缺乏分析。为了解决这两个问题，我们设计了一个实例级人类解析网络，该网络在像素级别上无锚固且可解决。它由两个简单的子网络组成：一个用于边界框预测的无锚检测头和一个用于人体分割的边缘引导解析头。无锚探测器的头继承了像素样的优点，并有效地避免了对象检测应用中证明的超参数的敏感性。通过引入部分感知的边界线索，边缘引导的解析头能够将相邻的人类部分与彼此区分开，最多可在一个人类实例中，甚至重叠的实例。同时，利用了精炼的头部整合盒子级别的分数和部分分析质量，以提高解析结果的质量。在两个多个人类解析数据集（即CIHP和LV-MHP-V2.0）和一个视频实例级人类解析数据集（即VIP）上进行实验，表明我们的方法实现了超过全球级别和实例级别的性能最新的一阶段自上而下的替代方案。

Recent one-stage object detectors follow a per-pixel prediction approach that predicts both the object category scores and boundary positions from every single grid location. However, the most suitable positions for inferring different targets, i.e., the object category and boundaries, are generally different. Predicting all these targets from the same grid location thus may lead to sub-optimal results. In this paper, we analyze the suitable inference positions for object category and boundaries, and propose a prediction-target-decoupled detector named PDNet to establish a more flexible detection paradigm. Our PDNet with the prediction decoupling mechanism encodes different targets separately in different locations. A learnable prediction collection module is devised with two sets of dynamic points, i.e., dynamic boundary points and semantic points, to collect and aggregate the predictions from the favorable regions for localization and classification. We adopt a two-step strategy to learn these dynamic point positions, where the prior positions are estimated for different targets first, and the network further predicts residual offsets to the positions with better perceptions of the object properties. Extensive experiments on the MS COCO benchmark demonstrate the effectiveness and efficiency of our method. With a single ResNeXt-64x4d-101-DCN as the backbone, our detector achieves 50.1 AP with single-scale testing, which outperforms the state-of-the-art methods by an appreciable margin under the same experimental settings.Moreover, our detector is highly efficient as a one-stage framework. Our code is public at https://github.com/yangli18/PDNet.

We present a simple, fully-convolutional model for realtime instance segmentation that achieves 29.8 mAP on MS COCO at 33.5 fps evaluated on a single Titan Xp, which is significantly faster than any previous competitive approach. Moreover, we obtain this result after training on only one GPU. We accomplish this by breaking instance segmentation into two parallel subtasks: (1) generating a set of prototype masks and (2) predicting per-instance mask coefficients. Then we produce instance masks by linearly combining the prototypes with the mask coefficients. We find that because this process doesn't depend on repooling, this approach produces very high-quality masks and exhibits temporal stability for free. Furthermore, we analyze the emergent behavior of our prototypes and show they learn to localize instances on their own in a translation variant manner, despite being fully-convolutional. Finally, we also propose Fast NMS, a drop-in 12 ms faster replacement for standard NMS that only has a marginal performance penalty.

我们提出了一种基于动态卷积的3D点云的实例分割方法。这使其能够在推断时适应变化的功能和对象尺度。这样做避免了一些自下而上的方法的陷阱，包括对超参数调整和启发式后处理管道的依赖，以弥补物体大小的不可避免的可变性，即使在单个场景中也是如此。通过收集具有相同语义类别并为几何质心进行仔细投票的均匀点，网络的表示能力大大提高了。然后通过几个简单的卷积层解码实例，其中参数是在输入上生成的。所提出的方法是无建议的，而是利用适应每个实例的空间和语义特征的卷积过程。建立在瓶颈层上的轻重量变压器使模型可以捕获远程依赖性，并具有有限的计算开销。结果是一种简单，高效且健壮的方法，可以在各种数据集上产生强大的性能：ScannETV2，S3DIS和Partnet。基于体素和点的体系结构的一致改进意味着提出的方法的有效性。代码可在以下网址找到：https：//git.io/dyco3d

在这项工作中，我们呈现SEQFormer，这是一个令人沮丧的视频实例分段模型。 SEQFormer遵循Vision变换器的原理，该方法模型视频帧之间的实例关系。然而，我们观察到一个独立的实例查询足以捕获视频中的时间序列，但应该独立地使用每个帧进行注意力机制。为此，SEQFormer在每个帧中定位一个实例，并聚合时间信息以学习视频级实例的强大表示，其用于动态地预测每个帧上的掩模序列。实例跟踪自然地实现而不进行跟踪分支或后处理。在YouTube-VIS数据集上，SEQFormer使用Reset-50个骨干和49.0 AP实现47.4个AP，其中Reset-101骨干，没有响铃和吹口哨。此类成果分别显着超过了以前的最先进的性能4.6和4.4。此外，与最近提出的Swin变压器集成，SEQFormer可以实现59.3的高得多。我们希望SEQFormer可能是一个强大的基线，促进了视频实例分段中的未来研究，同时使用更强大，准确，整洁的模型来实现该字段。代码和预先训练的型号在https://github.com/wjf5203/seqformer上公开使用。